1. Cell Growth and Division
Biology
Ms. Lew

2. Vocabulary (p. 90-91) Cell Cycle Chromatin Chromosome DNA overload
Interphase
Sister Chromatid
Spindle Fiber
Interphase
Sister Chromatid
Spindle Fiber

3. What is the cell cycle? Interphase Mitosis Cytokinesis
During the cell cycle, a “parent” cell grows and divides to form 2 “daughter” cells.
The cycle has three main stages
Interphase
Mitosis
Cytokinesis

4. Remember the two reasons why cells divide rather than continue to grow larger:
DNA Overload
__________________________________
_________________________________DNA overload is when the DNA has too many tasks to do (such as making proteins) and not enough DNA to get the job done efficiently.
Exchanging Materials

5. The Cell Cycle
Animation

6. G1 M S G2

7. Interphase – G1 , S & G2 During Interphase cells:
G1 phase: Grow to mature size
Mitochondria and chloroplasts are duplicated
S phase: Replicate (copy) DNA
G2 phase: Prepare for cell division
Cell grows
Most of a cells life is spent in Interphase.

8. Chromosomes Are made of DNA, histones, chromatin
Each chromosome consists of sister chromatids attached at a centromere
Each sister chromatid is an exact copy

9. P M A T Mitosis – M phase The cells nucleus divides into two nuclei
There are four phases
Prophase
Metaphase
Anaphase
Telophase
P M A T

10. Animal Cell Mitosis- Video

11. Prophase 1st stage of Mitosis Chromatin condenses into chromosomes
Centrioles separate and a spindle fiber begins to form.
Nuclear membrane breaks down

12. Prophase

13. Metaphase 2nd Phase of Mitosis
Chromosomes line up in the middle of the cell.
Each chromosome is connected to a spindle fiber.

14. Metaphase

15. Anaphase 3rd Phase of Mitosis
The sister chromatids separate at the centromere and move to opposite ends of the cell.

16. Anaphase

17. Telophase 4th Stage of Mitosis
Chromosomes gather at opposite ends of the cells and lose their shapes (return to chromatin form)
Two new nuclear membranes form, one for each cell.

18. Telophase

19. Cytokinesis The cytoplasm pinches in half.
Each daughter cell has an identical set of duplicate chromosomes

20. Cytokinesis

21. Overview sim

22. Plant cell mitosis

23. And Another one…